1. Field of the Invention
This invention relates generally to thin film mirrors, and more particularly to a method of securing the mirror film to the frame, and the resulting product.
2. Description of the Prior Art
Much effort has been directed to providing mirrors useful in projection television equipment. Examples of patented mirror technology for various uses, some of which is for television equipment, can be found in my U.S. Pat. No. 5,930,058, and the references cited therein. The content of that patent, to any extend needed, is incorporated herein by reference. With the advent of high-definition television (HD-TV), mirror improvements are desired. The present invention is addressed to that goal.
While mirrors made according to the present invention will be normally used with the reflecting face in a generally vertical attitude, the terminology used herein describes the mirror assembly as though lying in a horizontal plane.
According to one embodiment of the present invention, a multi-sided metal frame having a top surface is provided with a thermal insulating bead on the top surface, extending lengthwise of each side of the frame and spaced slightly inboard from the outer perimeter of the frame. A high-strength, fast-curing adhesive is provided atop the bead. A mirror film is applied to the bead and secured in place by the adhesive. The film portion within the area defined by the bead is tight and planar and retained in that condition by the cured adhesive. The thermal insulating means inhibits heat transmission between the adhesive and the frame and which would otherwise interfere with the desired curing time for the adhesive.
The method can be implemented by forming an elongate metal strip to give it a structural cross-sectional shape having a top face, applying the insulating bead along the top face, and then cutting and bending the strip as needed and connecting ends to form the frame. Then a frame back-board is installed and secured in the frame. Then the top of the bead is finished to be planar in a plane. Then the frame is held in a horizontal attitude with the face up and the adhesive is applied. Then mirror film is held tightly in a planar condition and then brought down upon the adhesive atop the bead. Then a platen descends, engaging the film portion above and in the layout pattern of the bead so that the film is disposed in a plane spaced from a plane containing the top surface of the frame. The film is thus held against the adhesive until the adhesive cures quickly to permanently fix the film in place relative to the frame without requiring additional adhesive or a long curing time.